In motor vehicles, one thinks of the use of image sensor systems for recording the vehicle environment. In particular, the use of image sensor systems in driver assistance systems is planned. For example, image sensor systems may be used for the automatic regulation of the distance of the motor vehicle from a vehicle traveling ahead.
To enlarge the image recording range, the use of several image sensor systems in the motor vehicle is planned, their recording ranges being able at least partially to overlap. In particular, the use of stereo cameras is provided that are made up of two image sensor systems, which photograph (take) essentially the same scene.
Methods and devices are known for calibrating image sensor systems in motor vehicles using a calibrating object.
For example, a non-prepublished German patent application number 10229336.8 (filed Jun. 29, 2002), discusses a device and a method for calibrating an image sensor system using a calibrating object and a position reference sensor.
European Patent reference EP 1 120 746 refers to a method for calibrating an image sensor system in a motor vehicle using a calibrating object. In this context, the calibrating object is connected to the motor vehicle and aligned with respect to the motor vehicle via a mechanical adjusting device. In this context, the calibration is performed with respect to the longitudinal axis of the motor vehicle. The longitudinal axis may be projected by symmetrical features of the motor vehicle, especially the vehicle body. On account of manufacturing tolerances, this longitudinal axis may not jibe with the geometrical travel axis, which is defined by the bisector of the rear axle's total toe-in angle. The deviations between the longitudinal axis and the geometrical travel axis are not negligible for a measuring image sensor system, especially when it is used in driver assistance systems in motor vehicles, since the geometrical axis of travel determines the travel direction in straight-ahead travel, independently of the position of the longitudinal axis.
References to the determination of the alignment of an image sensor system with respect to the geometrical travel axis of the motor vehicle, for calibrating an image sensor system, are missing from European Patent reference EP 1 120 746.